Photonics Dictionary: C

An optical material used in place of crown glass to produce lenses with extraordinary correction of chromatic aberrations. Its high coefficient of thermal expansion and its tendency to absorb...

An optical system in which the only image-forming elements are curved-surface mirrors; e.g., a Cassegrain lens system.

A CCD image sensor, or charge-coupled device image sensor, is a type of electronic device used to convert optical images into electronic signals. It is a key component in digital cameras, camcorders,...

The lens thickness measured at the optical axis.

1. Mounting a lens or mirror so that its optical axis is coincident with the optical or mechanical axes of other portions of the system. 2. The machining (edging) of the outside diameter of a lens...

In a perfectly centered lens, the mechanical axis (defined by the ground outside the diameter of the lens) is made to be exactly coincident with the optical axis (defined by a line through the...

Chalcogenide refers to a class of compounds containing elements from group 16 of the periodic table, which includes sulfur (S), selenium (Se), and tellurium (Te). These elements are known as...

Chirped mirrors are optical devices designed to manipulate the spectral properties of ultrashort laser pulses. They consist of multiple layers of dielectric coatings deposited on a substrate, where...

A rapid change, as opposed to a long-term drift, of the emission wavelength of an optical source. Chirping is most often observed in pulsed operation of a source.

Chromatic aberration is an optical phenomenon that occurs when different wavelengths (colors) of light are refracted by a lens or optical system, leading to a failure to focus all colors to the same...

In the optical field, a tube to which a lens is fastened for centering.

The limited light-gathering area of an optical system. The area is normally restricted to an edge or outer surface of an individual component. Also known as free aperture or objective aperture. The...

A fiber optic communications system that works on the principles of homodyning or heterodyning. The transmitting laser produces an optical wave that is modulated in amplitude, phase or frequency by...

A coherent fiber bundle (CFB), also known as a coherent fiber optic bundle, is an assembly of multiple optical fibers arranged in a specific geometric pattern to maintain the spatial coherence of...

An optical instrument consisting of a well- corrected objective lens or mirror with a light source and or object/image (i.e. illuminated slit or retical) at its focal plane. Collimators are used to...

A color center, in the context of materials science and condensed matter physics, refers to a specific type of crystallographic defect in a crystalline structure that introduces color to the...

1. A constituent part. It may consist of two or more parts cemented together, or with near and approximately matching surfaces. 2. The projection of a vector on a certain coordinate axis or along a...

A lens composed of two or more separate elements of optical glass that may or may not be cemented together. The surfaces of the elements are shaped to reduce or eliminate the aberrations inherent in...

A center-opening shutter made up of several identical leaves that are mounted symmetrically around the optical axis of the lens.

Concave is an adjective used to describe a surface or shape that curves inward or has a hollow or recessed appearance. In the context of geometry or optics, a concave shape is one that curves or...

Convex is an adjective used to describe a surface or shape that curves outward, bulges, or has a rounded and outwardly extending appearance. In the context of geometry or optics, a convex shape is...

A semispherical or conical lens created directly on the core of an optical fiber to focus light from a laser into the fiber core.

A corner cube, also known as a corner reflector or retroreflector prism, is a type of optical device used to reflect light or electromagnetic waves back towards their source with minimal deviation in...

In an optical system, the aperture size at which the lens gives its best overall performance.

One of the two principal types of optical glass, the other being flint glass. Crown glass is harder than flint glass, and has a lower index of refraction and lower dispersion. Both types are used in...

A custom optic refers to an optical component that is designed, manufactured, and tailored to meet specific requirements or applications. These optics can include lenses, mirrors, prisms, filters, or...

A cylindrical lens is an optical component that has different curvatures along its two orthogonal axes, resulting in a shape resembling a cylinder. Unlike spherical lenses, which have the same...